xfrm: Add refcount handling to queued policies
We need to ensure that policies can't go away as long as the hold timer
is armed, so take a refcont when we arm the timer and drop one if we
delete it.
Bug was introduced with git commit a0073fe18 ("xfrm: Add a state
resolution packet queue")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index ed38d5d..5f9be97 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -334,7 +334,8 @@
atomic_inc(&policy->genid);
- del_timer(&policy->polq.hold_timer);
+ if (del_timer(&policy->polq.hold_timer))
+ xfrm_pol_put(policy);
xfrm_queue_purge(&policy->polq.hold_queue);
if (del_timer(&policy->timer))
@@ -589,7 +590,8 @@
spin_lock_bh(&pq->hold_queue.lock);
skb_queue_splice_init(&pq->hold_queue, &list);
- del_timer(&pq->hold_timer);
+ if (del_timer(&pq->hold_timer))
+ xfrm_pol_put(old);
spin_unlock_bh(&pq->hold_queue.lock);
if (skb_queue_empty(&list))
@@ -600,7 +602,8 @@
spin_lock_bh(&pq->hold_queue.lock);
skb_queue_splice(&list, &pq->hold_queue);
pq->timeout = XFRM_QUEUE_TMO_MIN;
- mod_timer(&pq->hold_timer, jiffies);
+ if (!mod_timer(&pq->hold_timer, jiffies))
+ xfrm_pol_hold(new);
spin_unlock_bh(&pq->hold_queue.lock);
}
@@ -1787,8 +1790,9 @@
goto purge_queue;
pq->timeout = pq->timeout << 1;
- mod_timer(&pq->hold_timer, jiffies + pq->timeout);
- return;
+ if (!mod_timer(&pq->hold_timer, jiffies + pq->timeout))
+ xfrm_pol_hold(pol);
+ goto out;
}
dst_release(dst);
@@ -1819,11 +1823,14 @@
err = dst_output(skb);
}
+out:
+ xfrm_pol_put(pol);
return;
purge_queue:
pq->timeout = 0;
xfrm_queue_purge(&pq->hold_queue);
+ xfrm_pol_put(pol);
}
static int xdst_queue_output(struct sk_buff *skb)
@@ -1831,7 +1838,8 @@
unsigned long sched_next;
struct dst_entry *dst = skb_dst(skb);
struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
- struct xfrm_policy_queue *pq = &xdst->pols[0]->polq;
+ struct xfrm_policy *pol = xdst->pols[0];
+ struct xfrm_policy_queue *pq = &pol->polq;
if (pq->hold_queue.qlen > XFRM_MAX_QUEUE_LEN) {
kfree_skb(skb);
@@ -1850,10 +1858,12 @@
if (del_timer(&pq->hold_timer)) {
if (time_before(pq->hold_timer.expires, sched_next))
sched_next = pq->hold_timer.expires;
+ xfrm_pol_put(pol);
}
__skb_queue_tail(&pq->hold_queue, skb);
- mod_timer(&pq->hold_timer, sched_next);
+ if (!mod_timer(&pq->hold_timer, sched_next))
+ xfrm_pol_hold(pol);
spin_unlock_bh(&pq->hold_queue.lock);